#include <iostream>
#include <memory>
using std::cout;
using std::endl;
using std::shared_ptr;

void test(){
    shared_ptr<int> sp(new int(10));
    cout << sp.use_count() << endl;
    shared_ptr<int> sp2(sp);
    shared_ptr<int> sp3(new int(20));
    sp3 = sp;
    cout << sp.use_count() << endl;
}

int main()
{
    

    test ();
    return 0;
}

